package com.hmdp.utils;

import cn.hutool.core.lang.UUID;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.core.io.ClassPathResource;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.script.DefaultRedisScript;

import javax.annotation.Resource;
import java.util.Collection;
import java.util.Collections;
import java.util.concurrent.TimeUnit;

public class SimpleRedisLock implements ILock {

    private StringRedisTemplate stringRedisTemplate;
    private String name;

    public  SimpleRedisLock(String name, StringRedisTemplate stringRedisTemplate) {
        this.stringRedisTemplate = stringRedisTemplate;
        this.name = name;
    }

    private static final String KEY_PREFIX = "lock:";
    private static final String ID_PREFIX = UUID.randomUUID().toString(true) + "-";
    private static final DefaultRedisScript<Long> UNLOCK_SCRIPT;

    static {
        UNLOCK_SCRIPT = new DefaultRedisScript<>();
        UNLOCK_SCRIPT.setLocation(new ClassPathResource("unlock.lua"));
        UNLOCK_SCRIPT.setResultType(Long.class);
    }

    @Override
    public boolean tryLock(long timeoutSec) {
        //获取线程的标识
        String threadId = ID_PREFIX + Thread.currentThread().getId();
        String key = KEY_PREFIX + this.name;
        //获取锁
        Boolean success = this.stringRedisTemplate.opsForValue()
                .setIfAbsent(key, threadId, timeoutSec, TimeUnit.SECONDS);
        return Boolean.TRUE.equals(success);
    }

    @Override
    public void unlock() {
        //调用lua脚本
        this.stringRedisTemplate.execute(
                UNLOCK_SCRIPT,
                Collections.singletonList(KEY_PREFIX+this.name),
                ID_PREFIX+Thread.currentThread().getId()
        );
    }

/*    @Override
    public void unlock() {
        String key = KEY_PREFIX + this.name;
        String threadId = ID_PREFIX+Thread.currentThread().getId();
        String id = this.stringRedisTemplate.opsForValue().get(KEY_PREFIX+name);
        //判断标识是否一致
        if(threadId.equals(id)) {
            this.stringRedisTemplate.delete(key);
        }
    }*/
}
